Cutting device



June 23, 1964 E. A. HARTBAUER 3,138,074 CUTTING DEVICE Filed Feb. 1, 1962 4 Sheets-Sheet l Q as:

FIG- 6 INVENTOR. 5454/09? 4, #4878405? 54/4 q ieww June 23, 1964 E. A. HARTBAUER CUTTING DEVICE Filed Feb. 1, 1962 4 Sheets-Sheet 2 fie -2 INVENTOR.

June 23, 1964 E. A. HARTBAUER 3,138,074

ccccccccccc CE Sheets-Sheet 4 INVENTOR. Qua/airy 4, #4275414? BY 0% ,m

United States Patent 3,13%,974 CUTTING DEVICE Ellsworth A. Hartbauer, Concord, Califl, assignor to Crown Zellerbach Corporation, San Francisco, Calif.,

a corporation of Nevada Filed Feb. 1, 1962, Ser. No. 170,448 17 (Claims. (Cl. 93-8) This invention relates to a cutting device, and more particularly to a device for transversely severing longitudinally disposed material at predetermined locations along the length thereof. Cutting devices embodying the invention are especially useful in association with bagclosing machinery for severing the closure material or materials adjacent the bag extremities.

In the manufacture of most bags, whether singleor multiple-walled, a continuous sleeve or tube is first formed which is then cut into appropriate bag lengths. Usually, one end of each such bag length or tube is closed (sometimes both ends are closed, especially with valved bags) before being sent to the user who closes the other end of the bag after it has been filled. Bag closures take various forms depending on the material the bag is to receive, and conventional types of closures are plain sewing or stitching, tape over stitching, and stitching over tape. However, irrespective of the particular type of closure, the bag-closing operation is performed at high speed as a continuous process with the bags being successively advanced by a conveyor through a closing station. Necessarily then, the stitching and taping machines operate continuously and without interruption so that such tape and stitching extend between and interconnect the adjacent or successive bags and, consequently, it is necessary to sever the closure material that extends between adjacent bags.

Heretofore, such severance has been performed by chopper machines that have several inherent limitations and disadvantages-the most serious being that the cut or severance made thereby is ragged and extremely wasteful of material since the spacing between adjacent bags must be relatively great in order to afford the chopper sufiicient time and space in which to effect the severance. In this regard, it should be noted that the bags are being conveyed at a relatively high linear velocity, and that the chopper is stationary with respect to the direction of travel of the bags. As a consequence, the chopper delays the tape momentarily; and if there is appreciable slack in the tape, buckling thereof may result in the line of severance being angularly disposed which, quite apparently, necessitates the requirement of excessive spacing between adjacent bagswhich spacing cannot be accurately controlled.

Additionally, the operation of presently available chop pers is erratic in that the cutting knife must be rotated across the path of travel of the bags at an extremely high velocity, and because of this, actuation thereof cannot be positively synchronized and energized for each cutting operation. Therefore, the chopper is sometimes energized through several cycles of operation between two adjacent bags, which results in the wastage of tape; and at other times the chopper is not energized at all and the bags must be manually separated at a later time which disrupts the subsequent stacking, packaging, etc. operations. Moreover, it has been found that the choppers must be sharpened and replaced quite frequently since if they are to work at all, the tolerances of the cutting edges must be quite close.

In view of the foregoing, an object of the present invention is to provide an improved cutting device for transversely severing longitudinally extending material that may be moving in the longitudinal direction at relatively high speed. Another object of the invention is in the provision of a device having cutting blades that effectively move during a severing operation along the path of travel of a material being transversely severed thereby so that a positive, clean and accurate severance of such material is effected. Still another object is that of providing a cutting device of the type described that is positively energized at predetermined intervals and performs but one cutting operation for each separate energization thereof.

Yet another object is to provide a cutting device adapted for use with bag-closing machinery, and which provides a pair of rotatably mounted blade assemblies having their axes transversely oriented and respectively disposed on opposite sides of the plane of movement of bags leaving a closing station; each of the assemblies being equipped with a blade and being synchronously driven upon actuation thereof to rotate the blades about such axes in the direction of movement of the bags through intersecting arcs and into severing engagement to effect an accurately located transverse severance of the closure material extending between adjacent bags, whereby the spacing between the adjacent bags may be substantially reduced and a resulting savings of closure material attainedwhich in an ordinary bag line, will realize a monetary savings in the order of several thousand dollars per year.

A further object of the invention is to provide a cutting device of the character described in which the cutting blades are oriented and arranged to effect a scissors-like severance of the material cut thereby that continuously progresses from one transverse edge of such material to the other. Still a further object is in the provision of a cutting device of the type described in which the cutting blades define a point contact at any selected time during the severing engagement thereof, and in which such point contact progressively moves along the length of such blades from one end to the other to effect a scissors-like severing operation, a self-sharpening blade action, and a substantially perfect severing engagement of the blades since any imperfections or variations along the lengths thereof are inherently obviated.

Yet a further object is that of providing a cutting device as described, wherein the blade assemblies are positively driven in rotation about their respective axes, but in which one of the blades is displaceable along its rotary arc with respect to its positive drive means and is driven in advance thereof by the other of the blades during the actual transverse severance of a material passing between the assemblies. Additional objects and advantages of the invention will become apparent as the specification develops.

A specific embodiment of the invention is illustrated in the accompanying drawings, in which- FIGURE 1 is a broken top plan view showing a cutting device embodying the invention in operative association with a bag-closing machine;

FIGURE 2 is a sectional view taken along the plane 22 of FIGURE 1, the section being considered as transverse relative to the direction of movement of bags along the closure machinery;

FIGURE 3 is a broken end view in elevation of the device looking toward the right in FIGURES 1 and 2, and in which portions of the structure are illustrated in section;

FIGURE 4 is a vertical sectional view taken along the plane 4-4 of FIGURE 2;

FIGURE 5 is a vertical sectional view taken along the plane 55 of FIGURE 2;

FIGURE 6 is a transverse sectional view taken along the plane 6-6 of FIGURE 1;

FIGURES 7, 8 and 9 are enlarged, broken and somewhat diagrammatic end views in elevation of the blade assemblies, respectively illustrating the severing engagement of the cutting blades at various moments during a severance operation; and

FIGURES 7A, 8A, and 9A are essentially diagrammatic views taken generally along a horizontal plane extending through the upper cutting blade in FIGURES 7 through 9, and they respectively correspond to the positions illustrated in those figures.

In FIGURE 1, the cutting device in its entirety is designated with the numeral it) and is shown in operative association with bag-closing machinery comprising a conveyor 11 adapted to advance a plurality of bags or bag tubes 12 along the plane of the drawing from top to bottom in the direction of the arrow, and comprising also a drive mechanism 13 which powers the conveyor 11, a stitching machine (not shown), and other apparatus in the bag-closing machinery as well as the cutting device which is in the nature of an attachment for the bagclosing machinery and, quite commonly, is driven directly by the conveyor or stitching machine. Customarily, the bag-closing machinery is adapted to accommodate closures of different types such as plain sewing, sewing over tape, and tape over sewing; and the tape itself may be of various forms such as pressure-sensitive, thermoplastic, etc. In the specific illustration of FIGURE 1, the bags 12 have a tape over sewing closure, and it is apparent that the two longitudinally spaced bags 12 are interconnected by a tape strip 14-tl1at portion of the tape extending between two adjacent bags being denoted by the dimension 14a.

The conveyor 11 may be of conventional form, and the one illustrated has a stationary table or bed 15 and a pair of endless link chains 16 (only one of which is shown) oriented along opposite longitudinal edges of the bed 15. The link chains 16 are equipped at spaced intervals therealong with outwardly extending lugs 17, and the longitudinal spacing between successive lugs defines a bag-receiving station. As the chains travel along their endless paths in the direction of the arrow shown in FIGURE 1, the lugs 17 engage an edge of a bag positioncd forwardly thereof and continuously advance the same along the bed 15 and through the various stations of the bag-closing machinery.

As is shown most clearly in FIGURES 1, 2 and 3, the drive mechanism 13 includes a platform 13 that may be affixed to such stitching machine or otherwise suitably supported as at spaced intervals therealong on standards 19 bolted or otherwise fixedly secured to the flooring therebelow. The platform 18 may be affixed to such standards by means of bolts 2t) that extend through elongated openings in the platform to permit longitudinal locating thereof. Supported along the platform 13 are conventional power means which include a shaft and gear composition, and power for the cutting device 10 is obtained through a drive sprocket 21 secured by bolts 22 to a power take-off gear provided by such composition. The cutting device 10 is secured by bolts 23 to a bar 24 which is anchored to the platform 18 by one or more bolts 25 that preferably extend through transversely elongated slots in the platform 18 to permit the device 10 to be properly located with respect to the conveyor 11.

A link chain 26 is entrained about both the drive sprocket 21 and a driven sprocket 27 supported for rotation about a shaft 29. The sprocket 27 is secured by a set screw or other suitable means to the continuously driven element of a clutch assembly 28 which may be of conventional design as, for example, a Hilliard standard type-6 single-revolution clutch. When the clutch is energized, as will be described hereinafter, the shaft 29 is rotated thereby, but otherwise the shaft is stationary and the sprocket 27 and attached clutch component rotate relative thereto.

The device 10 includes a perimetric frame 30 of generally square shape with one of the vertical legs thereof being discontinuous, as shown at 31, to permit a portion of the conveyor 11 to be positioned therein. The lower leg of the frame is slidably received within a groove or channel 32 provided along the bar 24, and is secured in position witLin such channel by the bolt structure 23. The shaft 29 extends through the opposite vertical legs of the frame 30, and is journalled for rotation adjacent its ends on bearings 33 and 34 which are respectively received within openings provided therefor in such legs. Spaced above the shaft 31 and oriented in substantially parallel relation therewith is a shaft 35 journalled for rotation at opposite end portions thereof in bearings 36 and 37 extending through openings provided therefor in the vertical legs of the frame 39.

Pinned to the shaft 29 by a set screw or otherwises secured thereto so as to rotate therewith is a collar or hub 33 adjustably anchored to a gear 39 by a plurality of cap screws 4i) that are threadedly received within the gear and extend through angularly elongated slots 41 in the hub 38 to permit the precise angular position of the gear relative to the hub to be adjustable, as shown most clearly in FIGURE 4. Secured by a plurality of cap screws 42 to the gear 3% is a lower or first blade assembly 4-3 which, in the specific form shown, includes a generally cylindrical roll 44 that provides a mounting for a transversely oriented knife or blade 45 extending substantially from end to end of the roll. Meshing with the gear 39 so as to be driven thereby is a gear 46 that is pinned or otherwise secured to the shaft 35 so as to rotatably drive the same, and the gear 46 is fixed by one or more bolts 47 to an upper or second blade assembly generally indicated by the numeral 48. In the specific form shown, the blade assembly 48 comprises a dr ve element 49 mounted upon the shaft 35, and it is the drive element 49 which is fixed to the gear 46 by the bolt 57. The blade assembly 43 further comprises a riven element 59 in the form of a generally cylindrical roll rotatably supported upon the shaft 35. The roll 50 provides a mounting for a knife or blade 51 which extends substantially from end to end of the roll and is coextensive in length with the blade 45.

The roll 59 is adapted to be positively rotated by the drive element 49, but may rotate relative thereto through a small angular distance, and through such distance, thererore, the roll can have a greater angular velocity than the drive element 49. The structural interrelationship providing these results is best seen in FIGURE 5, and referring thereto it is seen that the element 49 is of generally semi-cylindrical configuration and is equipped with a hardened drive pin 52 that is chordally disposed and extends slightly beyond the generally diametral surface of the drive element. The pin 52 is adapted to engage a threaded pin or screw 53 carried by the roll St) in alignment with the pin 52; and more specifically, and referring to FIGURE 2, it is seen that the roll 53 has a generally semi-cylindrical lip that overhangs the driven element 48 and the screw 53 extends through such lip. The screw 53 is adjustable and the extent to which it proyectscutwardly from the roll lip toward the pin 52 1S selectively variable. The screw may be fixed in any ad usten position thereof by a set screw 54 threadedly received in an opening provided therefor in the lip of the roll 50. Also disposed between the driven element 59 and overhanging lip of the roll 50 is a helical spring 55 respectively seated at its opposite ends in recesses provided therefor in the lip and in the driven element.

As viewed in FIGURE 5, the lower or first blade assembly 43 or roll 44 thereof is driven in a clockwise direction when the clutch 28 is energized; and consequently, the upper or second blade assembly 48 and particularly the element thereof will be positively driven in a counter-clockwise direction through the meshing gears 39 and 46. Therefore, the pin 52 will engage the screw 53 and thereby positively drive the roll 50. However, the roll 5i; can be angularly advanced slightly at a velocity somewhat greater than that of the driven element 49 against the biasing force of the spring 55, and the limit of the angular distance through which the roll 50 can be advanced or displaced relative to the drivenelement 49 is defined by the spacing between the facing surfaces 56 of the driven element and 57 of the lip. It is apparent that any relative movement between the roll and driven element is terminated by abutment of such surfaces 56 and 57, assuming that the spring can be compressed to the extent necessary to permit such abutment. This type of angular displacement of the roll 50 occurs during an actual severing operation, and will be described in detail hereinafter with particular reference to FIGURES 7 through 9.

Since the blade -assemblies43 and 48 are normally in a stationary condition, they must be repetitively and synchronously actuated in accordance with the advancement of successive bags 12 along the conveyor 11. In the specific structure under consideration, the lugs 17, which define the location of successive bags and advance the same along the conveyor, are employed to trigger the actuating mechanism for the blade assemblies. The structural arrangement by which this is accomplished is shown most clearly in FIGURES l, 2 and 6; and referring thereto, it is seen that the longitudinally spaced lugs 17 are moved successively into engagement with an abutment element 58 disposed in the path of movement of the lugs. The abutment element 58 is secured by a screw 59 to an arm 60 supported for rotation relative to a shaft 61 that is journalled for rotation in bearings 62 and 63 respectively positioned in the opposite end portions of a tube 64 rigidly carried by brackets 65 and 66 that are bolted or otherwise fixed to the frame 30. The location of the arm 68 along the shaft 61 is adjustable so as to permit the abutment element 58 to be accurately disposed in the path of movement of the lugs 17; and such adjustability of the arm and positive locating thereof is provided in part by a stop collar 67 having an integral sleeve or hub 67 coaxially mounted on the shaft 61 and being selectively slidable therealong. The collar 67 is secured at any selected position along the shaft by a lock structure or screw 68 threadedly received within the collar and which may be tightened against a flattened. surface 69 provided along the outer end portion of the shaft 61.

The flange portion of the stop 67 is located along one side of the arm 60, and adjacent the opposite side thereof is a collar 70 fixed on the stop sleeve 67' against relative rotation and axial displacement by set screw 71. The longitudinal location of the collar 70 along the shaft 61 is somewhat remote from the arm 60 so that a space is defined therebetween, and a helical spring 72 is coaxially mounted about the sleeve 67 within such space. One end of the spring 72 is turned laterally and extends into a recess provided therefor in the collar 71; and, similarly, the opposite end of the spring is turned laterally and seats within a recess provided therefor in the arm 60. Thus, the spring 72 defines a resilient couple between the arm 60 and collar 70 (and shaft 61 which is secured to the collar through the stop 67) by which the shaft 61 is rotated whenever the arm 68, or abutment element 58 thereof is engaged by each lug 17, and are swung upwardly thereby as the lug advances longitudinally along the conveyor.

The shaft 61 is constrained against longitudinal displacements with respect to the tube 64 by a stop collar 73 secured to the shaft adjacent one end of the tube and by a crank arm 74 secured to the shaft adjacent the opposite end of the tube. The crank arm 74 is disposed at substantially right angles to the rotational axis of the shaft 61, extends downwardly therefrom, and at its lower end is provided with an elongated slot 7 5 that slidably receives a pin 76 therein. The pin is normal to the plane of the crank arm 74 and is connected to a lever arm 77 oriented in substantially parallel relation with the arm 74. The lever arm 77 is secured by a set screw 78 to a rod or stub shaft 79 that is disposed in spaced apart and substantially parallel relation with the pin 76. The rod 79 is rotatably supported in suitable bearings 80 and 81 provided by a tubular support 82 which is anchored by a cap screw 84' to a support bracket 83. The bracket 83 is rigidly secured to the frame 30 by bolts or other suitable means.

The-rod 79 has a split collar 83 secured to the outer end thereof, and the collar is clamped to the rod by a screw 84 that freely extends through one segment of the collar and is threadedly received within the other segment thereof. The collar 83 has a generally cylindrical passage 85 extending therethrough at a location above the rod 79, and slidably received within this passage is an elongated rod 86 having a threaded end portion 87 (FIGURE 3) receiving a nut 88 thereon having an enlarged outer end portion and also a restricted inner end portion bearing against the collar 83. The restricted inner end of the nut 88 is provided about the surface thereof with a plurality of flattened surface portions angularly spaced apart and adapted to have a leaf spring 89 selectively bear thereagainst. The leaf spring 89 is fixed to the collar 83 by a screw 90, and it will be apparent that the spring is effective to releasably constrain the nut 88 in various positions of adjustment thereof against inadvertent or unintended rotation.

The rod 86 angles downwardly and forwardly through the collar 83 and has an elongated helical spring 91 coaxially mounted thereon which at its upper end seats against the collar and at its lower end it bears against a sleeve 92 telescopically receiving the rod 86 therein. The sleeve 92 is positively located along the rod by a latch pin 93 that extends transversely through both the sleeve and rod and projects outwardly therefrom for cooperative engagement with a stop pin 94 secured to the normally static or stationary element of the clutch 28. The weight of the rod 86, spring 91, sleeve 92 and latch pin 93 ordinarily biases this structural composition into the position shown in FIGURE 3 in which the sleeve 92 rests.

upon the stop pin 94 which is constrained against rotation by its engagement with the latch pin 93. The biasing weight of these elements may be supplemented by a spring 95 although this is not required ordinarily when the cutting device is disposed and oriented as shown in the drawings.

When a lug 17 engages the abutment element 58 and rotates the same and arm 60 in a counter-clockwise direction, as viewed in FIGURE 3, the shaft 61 is rotated in a counter-clockwise direction, as are the arms 74 and 77. As a result, the rod 79 is rotated in a counter-clockwise direction and, consequently, the collar 83, rod 86 and sleeve 92 have a counter-clockwise rotation enforced thereon which results in the withdrawal of the latch pin 93 from engagement with the stop pin 94, whereupon the clutch 28 is energized. Such energization is followed by rotation of the blade assemblies 43 and 48, which are permitted to rotate through but one complete revolution because as soon as the lug 17 passes under the abutment element 58, the shaft 61, rod 79, and attached structures rotate in the opposite or clockwise direction, whereupon the latch pin 93 is moved downwardly and into the circular path of travel of the stop pin 94. The moving stop pin then engages the stationary latch pin whereupon the driving engagement of the clutch 28 with the shaft 29 is terminated.

As stated hereinbefore, the cutting blade 45 is radially disposed along its entire length but tapers therealong with respect to the distance of its cutting edge to the axis of rotation of the shaft 29. The precise angle of taper or radial distance of the cutting edge at any point therealong from the axis of the shaft 29 is selectively adjustable, and such adjustment is accomplished through the structural arrangement in which the blade 1s carried within a radially disposed channel 96 extending along the length of the roll 44. The blade is positively fixed within such channel by means of a plurality of axially spaced set screws 97 that can be tightened against the blade, and a fine or incremental adjustment of the blade is accomplished by means of a plurality of axially spaced set screws 98 that are chordally oriented in the roll 44 and extend into the channel 96 to bear against the under surface of the blade. This same structural arrangement is employed with respect to the cutting blade 51 which is similarly mounted within the roll 50 of the blade assembly 43, but the various set screws are not illustrated in FIGURE since inclusion thereof would confuse the intended structural illustration. It may be noted that each longitudinal edge of the blades 45 and 51 has a cutting surface provided therealong which permits a sharp cutting surface to be provided simply by inverting each of the blades in their respective channels.

Adjustability of the blades is desirable since the interrelation thereof must be such that the end portion of the blade 45 having the greatest radial distance from the axis of the shaft 29 must initially engage the leading end portion of the angularly oriented blade 51 as the blades are rotated into severing engagement, and this relationship causes the angular blade 51 to extend across the radial blade 54 intermediate its ends. Consequently, the adjustment of the blades is important since improper clearance between the blades could cause them to engage at such point of crossover whereupon the rolls would bind and their rotational movement would be terminated. While the blades can be properly dimensioned during manufacture thereof, they are intended to be sharpened and used for considerable periods; and it follows that the precise positioning required can only be obtained by providing for blade adjustment since the dimensions of each blade will change with every sharpening thereof.

As seen most clearly in FIGURES 1 and 2, the shaft 35 extends laterally outwardly from the frame in the same direction as the clutch 28, and has mounted thereon a friction spring 99 that bears at one end against an annular collar 100 provided by the bearing 36 exteriorly of the frame 30, and at its other end the spring 99 seats against a nut 101 threadedly received upon the outer end of the shaft 35. The inner end of the bearing 36 is in abutment with the gear 46, and it is clear that the frictional resistance defined by such abutment may be changed by varying the force of the spring 99 through adjustment of the nut 101. Such frictional force tends to restrict the freedom of rotation of the gear 46 and the knife assembly 48, and establishes a continuous positive engagement between the gears 46 and 39 and prevents backlash therebetween; and adjustability of the spring force permits the degree of friction to be selectively varied to attain best performance of the device.

In operation of the cutting device, the sprocket 27 and clutch component attached thereto are continuously driven, the knife assemblies 43 and 48 are normally in a stationary condition, and bags or bag tubes 12 are advanced in succession along the conveyor 11 by the respective engagement of such bags with the longitudinally spaced lugs 17. Prior to being moved into operative relation with the cutting device, the bags 12 are advanced through a closing station where stitching and tape are applied to at least one end thereof, and the bags are so oriented along the conveyor that their closed ends pass between the knife assemblies 43 and 43, as shown in FIG- URES 1 and 2. As each lug 17 approaches and engages the abutment element 53, the arm 60 attached thereto is swung upwardly by the moving lug and the shaft 61 is rotated by the arm through the resilient couple defined by the collar 70 and spring 72. As a result, the rod 85 is swung upwardly because of its connection with the rod 61 through the heretofore described linkage composition, and such upward movement of the rod withdraws the latch pin 93 from the stop pin 94 whereupon the clutch 28 is energized and the shafts 2 9 and rotated thereby. The knife assemblies 43 and 43 are necessarily rotated because of their respective connection with the shafts 29 and 35, and they will rotate through only one revolution because as soon as the lug l7 clears the abutment element 53, the rod 86 swings downwardly to dispose the latch pin 93 in the path of travel of the stop pin 94. Engagement of the two pins Will deenergize the clutch, whereupon rotation of the shafts 29 and 35 is terminated as is rotation of the knife assemblies 43 and 48.

The tape strip 14 and stitching covered thereby, both of which interconnect successive bags, are oriented intermediate the ends of the blades 4-5 and 51, and in the specific illustration, are centrally oriented with respect thereto as shown most clearly in FIGURES 7A, 8A and 9A. Upon actuation of the knife assemblies (referring now to FIGURES 7 through 9, inclusive), the assembly 43 is rotated in a clockwise direction and the assembly 48 in a counter-clockwise direction, and the blades 45 and 51 are oriented with respect to the assemblies and with respect to the rotational movement thereof so that the blades are brought into cutting engagement along the plane of movement of the tape strip 14. In this respect, it should be noted that the rotational velocity of each of the assemblies 43 and 4-8 is selected so that the linear velocity of the blades 45 md 51 is substantially the same as the linear velocity of the tape strip 14 passing between the assemblies. Therefore, the blades 45 and 51 effectively move with the tape strip and at the same velocity thereof during the actual severance of the tape and stitching, and this relationship elfects a clean, sharp and straight transverse severance thereof.

As the blades 45 and 51 are advanced toward the plane of the tape strip 14 to sever the same, the angular orientation of the blade 51 causes it to cross or extend over the tapered blade 45 (as shown in FIGURE 7A) prior to the actual tape severance. The clearance between the blades must be suflicient to permit the upper blade 51 to overlie the lower blade 45 while the tape 14 is disposed therebetween. FIGURES 7 and 7A illustrate this condition and show the blades just prior to engagement thereof. Continued rotation of the assemblies 43 and 43 brings the blade 45, and more particularly the end portion thereof having the greatest radial dimension or distance from the shaft 29, into engagement with the leading end portion of the blade 51, and more particularly with the trailing surface thereof. Because of the crossover or overlying disposition of the blades, further rotation of the assemblies 43 and 48 tends to cause the blades to bind at their point of crossover because the clearance between the blades diminishes as the blades are rotated into positions substantially normal to the plane of the tape 14 for in such perpendicular condition the blades must have and do have a negative clearance.

Such intolerable condition of binding engagement does not occur, however, because as the spacing between the blades progressively diminishes, the lower tapered blade 4-5 begins to drive the upper blade 51 at an angular velocity slightly greater than that of the shaft 35 and drive element 49 secured thereto. This increase in the velocity of the upper blade 51 is accommodated by compression of the spring 55 as heretofore described, and the increment of the velocity increase of the upper blade is dependent upon and determined by the angular disposition thereofthat is, the angle defined between the blade 51 and a plane intersecting the same which is radially disposed with respect to the shaft 35. Thus, the leading edge of the lower blade 45 slides along the trailing edge of the blade 51 while driving the same, whereupon a scissors-like severance of the tape strip 14 occurs.

FIGURES 8 and 8A illustrate the blades 45 and 51 at a time subsequent to their initial engagement and more explicitly, after the point contact therebetween has advanced toward and into substantial adjacency with one longitudinal edge of the tape strip 14. It will be apparent in FIGURE 8 that the spring 55 has been compressed slightly as the blade 51 and roll 50 are angularly advanced relative to the drive element 49. FIGURES 9 and 9A illustrate the blades at a subsequent moment and after the point contact therebetween has advanced beyond the other longitudinal edge of the tape strip 14 and, therefore, such tape strip has been completely severed. FIGURE 9 indicates clearly that the spring 55 has been further compressed to accommodate the additional requisite displacement of the blade 51 and roll 50 relative to the drive element 49. The assemblies 43 and 48 continue to rotate to their starting positions, at which time the blades 45 and 51 are completely separated.

The cutting device can be timed or adjusted in one of two ways to orient or locate accurately the line of severance effected by the blades 45 and 51 across that section of the tape strip which interconnects adjacent bags. One such adjustment is limited in extent and may be considered to be a fine or vernier type adjustment. The other is in the form of a gross adjustment.

The fine adjustment is made by rotating in the appropriate direction the nut 88 which is in threaded engagement with the rod 86 and is biased against the split collar 83 by the spring 91. It will be apparent that such rotation of the nut 88 shifts the rod 86 along the longitudinal axis thereof with respect to the split collar 83; and, as a result, the location of the latch pin 93 will be changed either generally downwardly or generally upwardly, as viewed in FIGURE 3, depending upon the direction of rotation of the nut. Consequently, the location of the stop pin 94, when the clutch is de-energized, may be changed by this adjustment since the location of the stop pin is determined by the point of its engagement with the latch pin 93. It necessarily follows that the precise location of the blades 45 and 51 when the cutting assemblies are at rest will be changed in accordance therewith; and, therefore, if the blades 45 and 51 have a starting position that is rotationally closer to the plane of the bags 12, the severance of the tape strip 14 will occur more quickly than when the starting position of the blades is rotationally offset to a greater extent from the plane of the bags.

The gross adjustment or timing of the tape severance with respect to the advancing bags is accomplished by angularly shifting the location of the collar or hub 38 with respect to the gear 39, as shown most clearly in FIG- URES 2 and 4. The relative angular position of these two elements may be changed by removing the cap screws 49, which permits the hub and gear to be angularly shifted with respect to each other. This enables the two blade assemblies and the two gears 39 and 46 respectively secured thereto be be rotated without changing the position of the shaft 29 and relative location of the latch and stop pins 93 and 94, and then the starting position of the blades 45 and 51 can be located either rotationally closer to or remote from the plane of the bags 12. The elongated slots 41 which pass the cap screws therethrough permit a more limited adjustment than the gross adjustment just described, but somewhat greater degree of adjustment than the fine adjustment discussed with respect to the nut 88 and rod 86, and may be accomplished by loosening and without removing the screws 40.

While in the foregoing specification an embodiment of the invention has been set forth in considerable detail for the purpose of making an adequate disclosure thereof, it will be apparent to those skilled in the art that numerous changes may be made in such details without departing from the spirit and principles of the invention.

I claim:

1. In apparatus for severing a length of material at predetermined intervals therealong, means for advancing such length of material along a predetermined path, and a cutting device to which such length of material is advanced comprising first and second blade assemblies respectively disposed on opposite sides of such path of movement and being respectively mounted for rotation about spacedapart axes extending transversely thereof, first and second cutting blades respectively provided by said first and sec- 163 0nd blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat, structure associated with said first blade and blade assembly for accommodating a continuing relative angular displacement therebetween along the arcuate path of travel of said first blade to enable the same to be bodily displaced in its entirety from end to end thereof by said second blade relative to said first blade assembly all during such severing en gagement and for bodily returning said first blade to its predisplaced angular position relative to said first blade assembly subsequent to such severing engagement, and drive means for synchronously rotating said blade assemblies in opposite angular directions and in timed relation with the advancement of such material to effect during each cycle of rotation such engagement of said blades to sever such material at predetermined intervals therealong,

2. The apparatus of claim 1 in which said first blade assembly includes a driven element and a driving element therefor, said driven element being equipped with said first blade, and in which the aforesaid structure includes a resilient couple connecting said driven and driving elements and accommodating angular displacement in one direction of said driven element with respect to said driving element.

3. In apparatus for severing a length of material at predetermined intervals therealong, means for advancing such length of material along a predetermined path, and a cutting device to which such length of material is advanced comprising first and second blade assemblies respectively disposed on opposite sides of such path of movement and being respectively mounted for rotation about spaced-apart axes extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat,

said first blade being radially disposed along its length.

relative to its associated axis of rotation and said second blade being angularly offset along its length relative to the direction of rotation of its associated blade assembly to provide leading and trailing ends, structure associated with one of said blades and its blade assembly for accommodating a continuing relative angular displacement therebetween along the arcuate path of travel thereof to enable such one blade to be bodily displaced in its entirety from end to end thereof by the other of said blades all during such engagement to cause the point of severing contact between said blades to advance progressively along the lengths thereof from one end toward the other and for bodily returning said one blade to its predisplaced angular position relative to its blade assembly subsequent to such severing engagement, and drive means for synchronously rotating said blade assemblies in opposite angular directions and in timed relation with the advancement of such material to effect during each cycle of rotation such engagement of said blades to sever such material at predetermined intervals therealong.

4. The apparatus of claim 3 in which the aforesaid one blade and its blade assembly are said first blade and blade assembly.

7 5. In apparatus for severing a length of material at predetermined intervals therealong, means for advancing such length of material along a predetermined path, and a cutting device to which such length of material is advanced comprising first and second blade assemblies respectively disposed on opposite sides of such path of movement and being respectively mounted for rotation about spaced-apart axes, extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said reams blades into severing engagement thereat, said first blade being radially disposed along its length relative to its associated axis of rotation and progressively diminishing with respect thereto in its radial dimension from one end toward the other, said second blade being angularly ofiset along its length relative to the direction of rotation of its associated blade assembly to provide leading and trailing ends respectively corresponding to the end portions of said first blade respectively having the greatest and smallest radial dimensions, structure associated with one of said blades and its blade assembly for accommodating a continuing relative angular displacement therebetween along the arcuate path of travel thereof to enable such one blade to be bodily displaced in its entirety from end to end thereof by the other of said blades all during such engagement to cause the point of severing contact between said blades to advance progressively along the lengths thereof from one end toward the other and for bodily returning said one blade to its predisplaced angular position relative to its blade assembly subsequent to such severing engagement, and drive means for synchronously rotating said blade assemblies in opposite angular directions and in timed relation with the advancement of such material to effect during each cycle of rotation such engagement of said blades to sever such material at predetermined intervals therealong.

6. The apparatus of claim 5 in which the aforesaid one blade and its blade assembly are said first blade and blade assembly.

7. The combination with apparatus for closing an end of a bag tube having means for advancing a succession of bag tubes through a closing station whereat each such end is closed by the application of tape or the like thereto; of a cutting device to which such bag tubes are advanced subsequent to the closing of each such end thereof, said cutting device comprising first and second blade assemblies respectively disposed on opposite sides of the path of movement of such bag tubes and being respectively mounted for rotation about spaced-apart axes extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat, said first blade being radially disposed along its length relative to its associated axis of rotation and said second blade being angularly offset along its length relative to the direction of rotation of its associated blade assembly to provide leading and trailing ends, structure associated with said first blade and blade assembly for accommodating relative angular displacement therebetween along the arcuate path of travel thereof to enable said first blade to be bodily accelerated in its entirety from end to end thereof by said second blade during such engagement to cause the point of severing contact between said blades to advance progressively along the lengths thereof from the leading toward the trailing end portion of said second blade, drive means for rotating said blade assemblies in opposite angular directions to bring said cutting blades into severing engagement during each such rotation, and actuating means for energizing said drive means in timed relation with the advancement of successive bag tubes to sever such tape or the like between successive bag tubes.

8. The combination with apparatus for closing an end of a bag tube having means for advancing a succession of bag tubes through a closing station whereat each such end is closed by the application of tape or the like thereto; of a cutting device to which such bag tubes are advanced subsequent to the closing of each such end thereof, said cutting device comprising first and second blade assemblies respectively disposed on opposite sides of the path of movement of such bag tubes and being respectively mounted for rotation about spaced-apart axes extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat, said first blade being radially disposed along its length relative to its associated axis of rotation and progressively diminishing with respect thereto in its radial dimension from one end toward the other, said second blade being angularly ofiset along its length relative to the direction of rotation of its associated blade assembly to provide leading and trailing ends respectively corresponding to the end portions of said first blade respectively having the greatest and smallest radial dimensions, structure associated with said first blade and blade assembly for accommodating relative angular displacement therebetween along the arcuate path of travel thereof to enable said first blade to be bodily accelerated in its entirety from end to end thereof by said second blade during such engagement to cause the point of severing contact between said blades to advance progressively along the lengths thereof from the leading toward the trailing end portion of said second blade, drive means for rotating said blade assemblies in opposite angular directions to bring said cutting blades into severing engagement during each such rotation, and actuating means for energizing said drive means in timed relation with the advancement of successive bag tubes to sever such tape or the like between successive bag tubes.

9. The combination with apparatus for closing an end of a bag tube having means for advancing a succession of bag tubes through a closing station whereat each such end of the successive bags are closed by a continuous tape strip or the like applied thereto and extending therebetween; of a cutting device to which such bag tubes are advanced subsequent to the closing of each such end thereof, said cutting device comprising first and second blade assemblies respectively disposed on opposite sides of the path of movement of such bag tubes and being respectively mounted for rotation about spaced-apart axes extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat, said first blade being radially disposed along its length relative to its associated axis of rotation and progressively diminishing with respect thereto in its radial dimension from one end toward the other, said second blade being angularly offset along its length relative to the direction of rotation of its associated blade assembly to provide leading and trailing ends respectively corresponding to the end portions of said first blade respectively having the greatest and smallest radial dimensions, structure associated with said first blade and blade assembly for accommodating relative angular displacement therebetween along the arcuate path of travel thereof to enable said first blade to be bodily advanced in its entirety from end to end thereof by said second blade during such engagement to cause the point of severing contact between said blades to advance progressively along the lengths thereof from the leading toward the trailing end portion of said second blade and for bodily returning said first blade to its preadvanced angular position relative to said first blade assembly subsequent to such severing engagement, selectively operable drive means for synchronously rotating said blade assemblies in opposite angular directions to effect during each cycle of rotation thereof such severing engagement of said blades, said drive means being operative to enforce on said drive assemblies an angular velocity such that the peripheral velocity of said cutting blades during such severing engagement thereof approximates the rate of advancement of such bag tubes, and actuating means operatively arranged with said first-mentioned means for energizing said drive means in timed relation with the advancement of successive bag 13 tubes to sever such tape or the like between successive bag tubes.

10. The combination of claim 9 in which said drive means includes a single-revolution clutch assembly operative upon each energization thereof to rotate said blade assemblies through one revolution, said actuating means being operative to repetitively energize said drive means to effect the aforesaid severance between successive bag tubes, and in which said first blade assembly includes a driven element and a driving element therefor, said driven element being equipped with said first blade, the aforesaid structure including a resilient couple connecting said driven and driving elements and accommodating angular displacement in one direction of said driven element with respect to said driving element.

11. In a cutting device for severing a length of material at predetermined intervals therealong as such material is advanced along a predetermined path, first and second blade assemblies respectively disposed on opposite sides of such path of movement and being respectively mounted for rotation about spaced-apart axes extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat, one of said blades being angularly offset along its length relative to the direction of rotation thereof to provide leading and trailing ends, structure accommodating a continuing change in the angular velocity of one of said cutting blades along the entire length thereof relative to the other all during such severing engagement to cause the point of severing contact between said blades to advance progressively along the lengths thereof from one end toward the other, and drive means for synchronously rotating said blade assemblies in opposite angular directions to efiect during each cycle of rotation thereof such severing engagement of said blades.

12. The cutting device of claim 11 in which said structure accommodates a positive acceleration in the angular velocity of the aforesaid one blade relative to its direction of rotation.

13. The cutting device of claim 12 in which the angularly offset blade and the angularly acceleratable blade are the same.

14. The cutting device of claim 13 in which the other of said cutting blades is radially disposed along its length relative to its associated axis of rotation.

15. The combination with apparatus for closing the ends of a succession of bag tubes advanced through a closing station whereat each such end of the successive bag tubes is closed by a continuous tape strip or the like applied thereto and extending between adjacent bag tubes of a cutting device to which such bag tubes are advanced subsequent to the closing of each such end thereof, said cutting device comprising first and second blade assemblies respectively disposed on opposite sides of the path of movement of such bag tubes and being respectively mounted for rotation about spaced-apart and substantially parallel axes extending transversely thereof, first and second cutting blades respectively provided by said first and second blade assemblies for rotation thereby about the respectively associated axes and through arcuate paths that intersect along such path of movement to bring said blades into severing engagement thereat, said first blade being radially disposed along its length relative to its associated axis of rotation and said second blade being angularly offset along its length relative to the direction of rotation thereof to provide leading and trailing ends, said second blade assembly including both a drive element and a driven element the latter of which fixedly carries said second cutting blade, said driven element being angularly displaceable relative to said drive element about the associated axis of rotation, structure normally defining a driving connection from said drive element to said driven element but accommodating a continuing positive angular acceleration of the driven element relative to the drive element to enable said second blade to be bodily advanced along its entire length by said first blade all during such severing engagement thereof to cause the point of severing contact between said blades to advance progressively along the lengths thereof from the leading to the trailing end of said second blade, selectively operable drive means for synchronously rotating said blade assemblies in opposite angular directions at an angular velocity such that the peripheral velocity of said cutting blades during such severing engagement thereof approximates the rate of advancement of such bag tubes, and actuating means operatively arranged with the aforesaid advancing means for energizing said drive means in timed relation with the advancement of successive bag tubes to sever such tape or the like extending between successive bag tubes.

16. The combination of claim 15 in which said first blade progressively diminishes along its length in radial dimension from the end thereof corresponding to the leading end of said second blade.

17. The combination of claim 16 in which said structure comprises spring means resiliently urging said driven element into driving engagement with said drive element and affording the aforesaid angular advancement of said driven element and the cutting blade carried thereby.

References Cited in the file of this patent UNITED STATES PATENTS 709,408 Jahnz Sept. 16, 1902 996,795 Rinner July 4, 1911 1,398,474 Strawn Nov. 29, 1921 1,840,232 Hartman Ian. 5, 1932 1,989,943 Potdevin Feb. 5, 1935 2,074,167 Cundall Mar. 16, 1937 2,657,510 Lewis Nov. 3, 1953 2,768,692 Engle Oct. 30, 1956 

1. IN APPARATUS FOR SEVERING A LENGTH OF MATERIAL AT PREDETERMINED INTERVALS THEREALONG, MEANS FOR ADVANCING SUCH LENGTH OF MATERIAL ALONG A PREDETERMINED PATH, AND A CUTTING DEVICE TO WHICH SUCH LENGTH OF MATERIAL IS ADVANCED COMPRISING FIRST AND SECOND BLADE ASSEMBLIES RESPECTIVELY DISPOSED ON OPPOSITE SIDES OF SUCH PATH OF MOVEMENT AND BEING RESPECTIVELY MOUNTED FOR ROTATION ABOUT SPACEDAPART AXES EXTENDING TRANSVERSELY THEREOF, FIRST AND SECOND CUTTING BLADES RESPECTIVELY PROVIDED BY SAID FIRST AND SECOND BLADE ASSEMBLIES FOR ROTATION THEREBY ABOUT THE RESPECTIVELY ASSOCIATED AXES AND THROUGH ARCUATE PATHS THAT INTERSECT ALONG SUCH PATH OF MOVEMENT TO BRING SAID BLADES INTO SEVERING ENGAGEMENT THEREAT, STRUCTURE ASSOCIATED WITH SAID FIRST BLADE AND BLADE ASSEMBLY FOR ACCOMMODATING A CONTINUING RELATIVE ANGULAR DISPLACEMENT THEREBETWEEN ALONG THE ARCUATE PATH OF TRAVEL OF SAID FIRST BLADE TO ENABLE THE SAME TO BE BODILY DISPLACED IN ITS ENTIRETY FROM END TO END THEREOF BY SAID SECOND BLADE RELATIVE 